1. Field of the Invention
The present invention relates to the use of a drive tape to advance two tapes in mutual contact with the drive tape and, more particularly, to a method and apparatus for prolonging the useful life of such a drive tape.
2. Description of the Prior Art
Magnetic contact printers are used to transcribe signals from a master tape onto a copy tape. Both the master and copy tapes are driven in unison past a transcribing head which causes the signals recorded on the master tape to be duplicated on the copy tape. Typically, the master and copy tapes are advanced by a drive tape which is pressed together with the master and copy tapes.
The drive tape is made long enough to accommodate the longest master and copy tapes expected to be used. However, the length of the recorded portion on the master tape often is less than the length of the drive tape. In conventional printers the drive tape is rewound to its starting point each time a transcription operation is completed. Consequently, the beginning part of the drive tape wears out faster than the rest.
The physical condition of the drive tape deteriorates as it repeatedly rubs agains other parts of the printer. As the physical condition of the drive tape deteriorates, so does the quality of the transcription, until it becomes so poor that the drive tape must be replaced. In most cases the drive tape past the beginning portion is still in good condition when the beginning portion has already worn out. Therefore, the cost of drive tapes for such printers is unnecessarily high because they frequently have to be replaced before they are worn out over their entire length.